BroadcastReceiver意为广播接收,通过它可以实现进程间通信也可以实现进程内部进行通信,对于广播的消息我们只处理感兴趣的消息,可以接收系统的广播(短信、开机)也可以接收自定义的广播,但都需要注册才能接收,注册的方式又分两种,一是在AndroidMainfest.xml中注册,二是在代码中注册。
BroadcastReceiver是一个抽象的类,我们需要继承它才能创建对象
创建一个类ReceiveMsg.java继承BroadcastReceiver,并定义两个自定义的消息
package com.example.receivermsg; import android.content.BroadcastReceiver; import android.content.Context; import android.content.Intent; public class ReceiverMsg extends BroadcastReceiver { //定义两个自定义的消息 public static final String MSG = "com.example.msg"; public static final String REG_MSG = "com.example.reg.msg"; /** * 接收消息处理 */ @Override public void onReceive(Context arg0, Intent arg1) { // TODO Auto-generated method stub if(arg1.getAction().equals(MSG)){ System.out.println(MSG); } else if(arg1.getAction().equals(REG_MSG)){ System.out.println(REG_MSG); } } }在AndroidMainfest.xml文件中声明
<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.broadcastdemo" android:versionCode="1" android:versionName="1.0" > <uses-sdk android:minSdkVersion="8" android:targetSdkVersion="17" /> <application android:allowBackup="true" android:icon="@drawable/ic_launcher" android:label="@string/app_name" android:theme="@style/AppTheme" > <activity android:name="com.example.broadcastdemo.MainActivity" android:label="@string/app_name" > <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> <!-- 定义Broadcast Receiver 指定监听的Action --> <receiver android:name="com.example.receivermsg.ReceiverMsg"> <!-- 注册自定义的消息 --> <intent-filter > <action android:name="com.example.reg.msg"/> </intent-filter> </receiver> </application> <!-- 声明接收消息的权限 --> <uses-permission android:name="android.permission.RECEIVE_SMS" > </uses-permission> </manifest>
package com.example.broadcastdemo; import com.example.receivermsg.ReceiverMsg; import android.app.Activity; import android.content.Intent; import android.content.IntentFilter; import android.os.Bundle; import android.view.Menu; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; public class MainActivity extends Activity implements OnClickListener { private Button sendMsg = null; private Button sendReg = null; private ReceiverMsg receiver = null; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); sendMsg = (Button) findViewById(R.id.sendMsg); sendReg = (Button) findViewById(R.id.sendRegMsg); sendMsg.setOnClickListener(this); sendReg.setOnClickListener(this); // 生成一个BroiadcastReceiver对象 receiver = new ReceiverMsg(); // 生成一个IntentFilter对象 IntentFilter filter = new IntentFilter(); // 为IntentFilter添加一个Action filter.addAction(ReceiverMsg.MSG); // 将BroadcastReceiver对象注册到系统当中 registerReceiver(receiver, filter); } @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.main, menu); return true; } /** * 按钮监听 */ @Override public void onClick(View arg0) { // TODO Auto-generated method stub int id = arg0.getId(); // 用来区分点击的是哪个按钮 if (id == R.id.sendMsg) { Intent intent = new Intent(); intent.setAction(ReceiverMsg.MSG); sendBroadcast(intent); System.out.println("send own msg"); } else if (id == R.id.sendRegMsg) { Intent intent = new Intent(); intent.setAction(ReceiverMsg.REG_MSG); sendBroadcast(intent); System.out.println("send reg msg"); } } }在onReceive中接收到感兴趣的消息就可以根据需要进行处理,比如更新播放进度、更新时间等操作。
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